Yes, you're of course correct, probably most of the movements would not really constitute a part of a "GDP". But even if 80% of the "sent coins" (excluding the change) would be covered by consolidations by service providers, mixing/coinjoins and other use cases, I would have still expected a lower value.

I'd love to see some stats about this but I haven't found any charts about consolidation transactions as I expect them to be the biggest group of "non-GDP transactions" due to their generally huge value and their efficient space usage. At mempool.space it seems that consolidations make up around a third of the transaction size. Judging by the incentives to move coins for a certain fee, I expect the impact in the "sent USD" to be a little bit higher. I'd estimate it at 50%.